Recently, sales of merchandise by a so-called e-commerce in which a user orders merchandise over the Internet and then a trader who has received the order delivers the merchandise to a specified receiving location, such as the user's home or the home nearby convenience store, are gradually activated.
It is important to load merchandise by laying the merchandise without leaving a useless space in a cargo space of the transport means, for example a truck, such that the trader received the order delivers the merchandise to as many users as possible in a short period of time.
In a case where the trader stores the merchandise in the storehouse until the trader receives an order, it is important to load the merchandise by laying the merchandise without leaving a useless space in the storehouse in the same manner as described above, such that the trader stores as much the merchandises as possible in one storehouse.
A technique relating to the above loading is disclosed in PTL 1.